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getttyen(3) [minix man page]

GETTTYENT(3)						     Library Functions Manual						      GETTTYENT(3)

getttyent, getttynam, setttyent, endttyent - interface to /etc/ttytab SYNOPSIS
#include <ttyent.h> struct ttyent *getttyent(void) struct ttyent *getttynam(const char *name) int setttyent(void) void endttyent(void) DESCRIPTION
The getttyent functions provide an interface to the /etc/ttytab. (See ttytab(5)). To read one of these files one calls getttyent() several times to read the entries in the table until NULL is returned for end-of-file. Getttyname() searches the ttytab file for the given terminal device. It is equivalent to a call to setttyent(), several calls to gett- tyent() to locate the entry, and a final endttyent() to close the file. Setttyent() opens or rewinds the ttytab database, and endttyent() closes it. Getttyent() opens the database if not already open, but does not close it. The struct ttyent is defined by <ttyent.h> as follows: struct ttyent { char *ty_name; /* Name of the terminal device. */ char *ty_type; /* Terminal type name (termcap(3)). */ char **ty_getty; /* Program to run, normally getty. */ char **ty_init; /* Initialization command, normally stty. */ }; A valid entry has at least two strings, so both ty_name and ty_type are filled in. The optional ty_getty and ty_init may be NULL (field omitted), point to a pointer that is NULL (null lenght field, i.e. ""), or an array of strings terminated by a NULL (field present). For now no useful distinction can be made between a omitted field and an empty field, so treat both cases as an omission. FILES
/etc/ttytab The terminal device database SEE ALSO
ttyname(3), ttyslot(3), ttytab(5), init(8). DIAGNOSTICS
Setttyent() has the same return value and error codes as the open(2) call it uses to open the ttytab file. The getxxx() functions return NULL on end of file, entry not found, or error. You can set errno to zero before the call and check it after. NOTES
Getttyent() and getttynam() return a pointer to static storage that is overwritten in each call. The Minix struct ttyent has only the ty_name and ty_type fields in common with the BSD implementation. This does not seem to be a problem, because most third party software that need to know about terminals only look at the ty_name field. AUTHOR
Kees J. Bot ( GETTTYENT(3)

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GETTTYENT(3)                                                 Linux Programmer's Manual                                                GETTTYENT(3)

getttyent, getttynam, setttyent, endttyent - get ttys file entry SYNOPSIS
#include <ttyent.h> struct ttyent *getttyent(void); struct ttyent *getttynam(const char *name); int setttyent(void); int endttyent(void); DESCRIPTION
These functions provide an interface to the file _PATH_TTYS (e.g., /etc/ttys). The function setttyent() opens the file or rewinds it if already open. The function endttyent() closes the file. The function getttynam() searches for a given terminal name in the file. It returns a pointer to a ttyent structure (description below). The function getttyent() opens the file _PATH_TTYS (if necessary) and returns the first entry. If the file is already open, the next entry. The ttyent structure has the form: struct ttyent { char *ty_name; /* terminal device name */ char *ty_getty; /* command to execute, usually getty */ char *ty_type; /* terminal type for termcap */ int ty_status; /* status flags */ char *ty_window; /* command to start up window manager */ char *ty_comment; /* comment field */ }; ty_status can be: #define TTY_ON 0x01 /* enable logins (start ty_getty program) */ #define TTY_SECURE 0x02 /* allow UID 0 to login */ ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). +--------------------------+---------------+-----------------------+ |Interface | Attribute | Value | +--------------------------+---------------+-----------------------+ |getttyent(), setttyent(), | Thread safety | MT-Unsafe race:ttyent | |endttyent(), getttynam() | | | +--------------------------+---------------+-----------------------+ CONFORMING TO
Not in POSIX.1. Present on the BSDs, and perhaps other systems. NOTES
Under Linux, the file /etc/ttys, and the functions described above, are not used. SEE ALSO
ttyname(3), ttyslot(3) COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at GNU 2017-09-15 GETTTYENT(3)
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